diff --git a/novelwriter/constants.py b/novelwriter/constants.py
index 39fd7a69..0ba85a57 100644
--- a/novelwriter/constants.py
+++ b/novelwriter/constants.py
@@ -67,7 +67,7 @@ class nwRegEx:
     FMT_EI = r"(?<![\w\\])(_)(?![\s_])(.+?)(?<![\s\\])(\1)(?!\w)"
     FMT_EB = r"(?<![\w\\])([\*]{2})(?![\s\*])(.+?)(?<![\s\\])(\1)(?!\w)"
     FMT_ST = r"(?<![\w\\])([~]{2})(?![\s~])(.+?)(?<![\s\\])(\1)(?!\w)"
-    FMT_SC = r"(?i)(?<!\\)(\[[\/\!]?(?:i|b|s|u|sup|sub)\])"
+    FMT_SC = r"(?i)(?<!\\)(\[[\/\!]?(?:i|b|s|u|m|sup|sub)\])"
     FMT_SV = r"(?<!\\)(\[(?i)(?:fn|footnote):)(.+?)(?<!\\)(\])"
 
     # Pre-Compiled RegEx
@@ -86,6 +86,8 @@ class nwShortcode:
     STRIKE_C = "[/s]"
     ULINE_O  = "[u]"
     ULINE_C  = "[/u]"
+    MARK_O   = "[m]"
+    MARK_C   = "[/m]"
     SUP_O    = "[sup]"
     SUP_C    = "[/sup]"
     SUB_O    = "[sub]"
diff --git a/novelwriter/core/tokenizer.py b/novelwriter/core/tokenizer.py
index 495d3e07..22bf0e85 100644
--- a/novelwriter/core/tokenizer.py
+++ b/novelwriter/core/tokenizer.py
@@ -74,10 +74,12 @@ class Tokenizer(ABC):
     FMT_D_E   = 6   # End strikeout
     FMT_U_B   = 7   # Begin underline
     FMT_U_E   = 8   # End underline
-    FMT_SUP_B = 9   # Begin superscript
-    FMT_SUP_E = 10  # End superscript
-    FMT_SUB_B = 11  # Begin subscript
-    FMT_SUB_E = 12  # End subscript
+    FMT_M_B   = 9   # Begin mark
+    FMT_M_E   = 10  # End mark
+    FMT_SUP_B = 11  # Begin superscript
+    FMT_SUP_E = 12  # End superscript
+    FMT_SUB_B = 13  # Begin subscript
+    FMT_SUB_E = 14  # End subscript
 
     # Block Type
     T_EMPTY    = 1   # Empty line (new paragraph)
@@ -187,6 +189,7 @@ class Tokenizer(ABC):
             nwShortcode.BOLD_O:   self.FMT_B_B,   nwShortcode.BOLD_C:   self.FMT_B_E,
             nwShortcode.STRIKE_O: self.FMT_D_B,   nwShortcode.STRIKE_C: self.FMT_D_E,
             nwShortcode.ULINE_O:  self.FMT_U_B,   nwShortcode.ULINE_C:  self.FMT_U_E,
+            nwShortcode.MARK_O:   self.FMT_M_B,   nwShortcode.MARK_C:   self.FMT_M_E,
             nwShortcode.SUP_O:    self.FMT_SUP_B, nwShortcode.SUP_C:    self.FMT_SUP_E,
             nwShortcode.SUB_O:    self.FMT_SUB_B, nwShortcode.SUB_C:    self.FMT_SUB_E,
         }
diff --git a/novelwriter/enum.py b/novelwriter/enum.py
index aa9106e3..85724c95 100644
--- a/novelwriter/enum.py
+++ b/novelwriter/enum.py
@@ -124,8 +124,9 @@ class nwDocAction(Enum):
     SC_BOLD   = 31
     SC_STRIKE = 32
     SC_ULINE  = 33
-    SC_SUP    = 34
-    SC_SUB    = 35
+    SC_MARK   = 34
+    SC_SUP    = 35
+    SC_SUB    = 36
 
 # END Enum nwDocAction
 
diff --git a/novelwriter/gui/doceditor.py b/novelwriter/gui/doceditor.py
index 192b00ef..31233002 100644
--- a/novelwriter/gui/doceditor.py
+++ b/novelwriter/gui/doceditor.py
@@ -769,6 +769,8 @@ class GuiDocEditor(QPlainTextEdit):
             self._wrapSelection(nwShortcode.STRIKE_O, nwShortcode.STRIKE_C)
         elif action == nwDocAction.SC_ULINE:
             self._wrapSelection(nwShortcode.ULINE_O, nwShortcode.ULINE_C)
+        elif action == nwDocAction.SC_MARK:
+            self._wrapSelection(nwShortcode.MARK_O, nwShortcode.MARK_C)
         elif action == nwDocAction.SC_SUP:
             self._wrapSelection(nwShortcode.SUP_O, nwShortcode.SUP_C)
         elif action == nwDocAction.SC_SUB:
@@ -2313,6 +2315,13 @@ class GuiDocToolBar(QWidget):
             lambda: self.requestDocAction.emit(nwDocAction.SC_ULINE)
         )
 
+        self.tbMark = QToolButton(self)
+        self.tbMark.setIconSize(iconSize)
+        self.tbMark.setToolTip(self.tr("Shortcode Mark"))
+        self.tbMark.clicked.connect(
+            lambda: self.requestDocAction.emit(nwDocAction.SC_MARK)
+        )
+
         self.tbSuperscript = QToolButton(self)
         self.tbSuperscript.setIconSize(iconSize)
         self.tbSuperscript.setToolTip(self.tr("Shortcode Superscript"))
@@ -2339,6 +2348,7 @@ class GuiDocToolBar(QWidget):
         self.outerBox.addWidget(self.tbItalic)
         self.outerBox.addWidget(self.tbStrike)
         self.outerBox.addWidget(self.tbUnderline)
+        self.outerBox.addWidget(self.tbMark)
         self.outerBox.addWidget(self.tbSuperscript)
         self.outerBox.addWidget(self.tbSubscript)
         self.outerBox.setContentsMargins(cM, cM, cM, cM)
diff --git a/novelwriter/gui/mainmenu.py b/novelwriter/gui/mainmenu.py
index ae99f6c2..88f6bf41 100644
--- a/novelwriter/gui/mainmenu.py
+++ b/novelwriter/gui/mainmenu.py
@@ -672,6 +672,12 @@ class GuiMainMenu(QMenuBar):
             lambda: self.requestDocAction.emit(nwDocAction.SC_ULINE)
         )
 
+        # Shortcode Mark
+        self.aScMark = self.mShortcodes.addAction(self.tr("Mark"))
+        self.aScMark.triggered.connect(
+            lambda: self.requestDocAction.emit(nwDocAction.SC_MARK)
+        )
+
         # Shortcode Superscript
         self.aScSuper = self.mShortcodes.addAction(self.tr("Superscript"))
         self.aScSuper.triggered.connect(